1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * bio-integrity.c - bio data integrity extensions
4 *
5 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
6 * Written by: Martin K. Petersen <[email protected]>
7 */
8
9 #include <linux/blk-integrity.h>
10 #include <linux/mempool.h>
11 #include <linux/export.h>
12 #include <linux/bio.h>
13 #include <linux/workqueue.h>
14 #include <linux/slab.h>
15 #include "blk.h"
16
17 static struct kmem_cache *bip_slab;
18 static struct workqueue_struct *kintegrityd_wq;
19
blk_flush_integrity(void)20 void blk_flush_integrity(void)
21 {
22 flush_workqueue(kintegrityd_wq);
23 }
24
25 /**
26 * bio_integrity_free - Free bio integrity payload
27 * @bio: bio containing bip to be freed
28 *
29 * Description: Free the integrity portion of a bio.
30 */
bio_integrity_free(struct bio * bio)31 void bio_integrity_free(struct bio *bio)
32 {
33 struct bio_integrity_payload *bip = bio_integrity(bio);
34 struct bio_set *bs = bio->bi_pool;
35
36 if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
37 if (bip->bip_vec)
38 bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
39 bip->bip_max_vcnt);
40 mempool_free(bip, &bs->bio_integrity_pool);
41 } else {
42 kfree(bip);
43 }
44 bio->bi_integrity = NULL;
45 bio->bi_opf &= ~REQ_INTEGRITY;
46 }
47
48 /**
49 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
50 * @bio: bio to attach integrity metadata to
51 * @gfp_mask: Memory allocation mask
52 * @nr_vecs: Number of integrity metadata scatter-gather elements
53 *
54 * Description: This function prepares a bio for attaching integrity
55 * metadata. nr_vecs specifies the maximum number of pages containing
56 * integrity metadata that can be attached.
57 */
bio_integrity_alloc(struct bio * bio,gfp_t gfp_mask,unsigned int nr_vecs)58 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
59 gfp_t gfp_mask,
60 unsigned int nr_vecs)
61 {
62 struct bio_integrity_payload *bip;
63 struct bio_set *bs = bio->bi_pool;
64 unsigned inline_vecs;
65
66 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
67 return ERR_PTR(-EOPNOTSUPP);
68
69 if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
70 bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
71 inline_vecs = nr_vecs;
72 } else {
73 bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
74 inline_vecs = BIO_INLINE_VECS;
75 }
76
77 if (unlikely(!bip))
78 return ERR_PTR(-ENOMEM);
79
80 memset(bip, 0, sizeof(*bip));
81
82 /* always report as many vecs as asked explicitly, not inline vecs */
83 bip->bip_max_vcnt = nr_vecs;
84 if (nr_vecs > inline_vecs) {
85 bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool,
86 &bip->bip_max_vcnt, gfp_mask);
87 if (!bip->bip_vec)
88 goto err;
89 } else if (nr_vecs) {
90 bip->bip_vec = bip->bip_inline_vecs;
91 }
92
93 bip->bip_bio = bio;
94 bio->bi_integrity = bip;
95 bio->bi_opf |= REQ_INTEGRITY;
96
97 return bip;
98 err:
99 if (bs && mempool_initialized(&bs->bio_integrity_pool))
100 mempool_free(bip, &bs->bio_integrity_pool);
101 else
102 kfree(bip);
103 return ERR_PTR(-ENOMEM);
104 }
105 EXPORT_SYMBOL(bio_integrity_alloc);
106
bio_integrity_unpin_bvec(struct bio_vec * bv,int nr_vecs)107 static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs)
108 {
109 int i;
110
111 for (i = 0; i < nr_vecs; i++)
112 unpin_user_page(bv[i].bv_page);
113 }
114
bio_integrity_uncopy_user(struct bio_integrity_payload * bip)115 static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
116 {
117 unsigned short orig_nr_vecs = bip->bip_max_vcnt - 1;
118 struct bio_vec *orig_bvecs = &bip->bip_vec[1];
119 struct bio_vec *bounce_bvec = &bip->bip_vec[0];
120 size_t bytes = bounce_bvec->bv_len;
121 struct iov_iter orig_iter;
122 int ret;
123
124 iov_iter_bvec(&orig_iter, ITER_DEST, orig_bvecs, orig_nr_vecs, bytes);
125 ret = copy_to_iter(bvec_virt(bounce_bvec), bytes, &orig_iter);
126 WARN_ON_ONCE(ret != bytes);
127
128 bio_integrity_unpin_bvec(orig_bvecs, orig_nr_vecs);
129 }
130
131 /**
132 * bio_integrity_unmap_user - Unmap user integrity payload
133 * @bio: bio containing bip to be unmapped
134 *
135 * Unmap the user mapped integrity portion of a bio.
136 */
bio_integrity_unmap_user(struct bio * bio)137 void bio_integrity_unmap_user(struct bio *bio)
138 {
139 struct bio_integrity_payload *bip = bio_integrity(bio);
140
141 if (bip->bip_flags & BIP_COPY_USER) {
142 if (bio_data_dir(bio) == READ)
143 bio_integrity_uncopy_user(bip);
144 kfree(bvec_virt(bip->bip_vec));
145 return;
146 }
147
148 bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt);
149 }
150
151 /**
152 * bio_integrity_add_page - Attach integrity metadata
153 * @bio: bio to update
154 * @page: page containing integrity metadata
155 * @len: number of bytes of integrity metadata in page
156 * @offset: start offset within page
157 *
158 * Description: Attach a page containing integrity metadata to bio.
159 */
bio_integrity_add_page(struct bio * bio,struct page * page,unsigned int len,unsigned int offset)160 int bio_integrity_add_page(struct bio *bio, struct page *page,
161 unsigned int len, unsigned int offset)
162 {
163 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
164 struct bio_integrity_payload *bip = bio_integrity(bio);
165
166 if (bip->bip_vcnt > 0) {
167 struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1];
168 bool same_page = false;
169
170 if (bvec_try_merge_hw_page(q, bv, page, len, offset,
171 &same_page)) {
172 bip->bip_iter.bi_size += len;
173 return len;
174 }
175
176 if (bip->bip_vcnt >=
177 min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
178 return 0;
179
180 /*
181 * If the queue doesn't support SG gaps and adding this segment
182 * would create a gap, disallow it.
183 */
184 if (bvec_gap_to_prev(&q->limits, bv, offset))
185 return 0;
186 }
187
188 bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
189 bip->bip_vcnt++;
190 bip->bip_iter.bi_size += len;
191
192 return len;
193 }
194 EXPORT_SYMBOL(bio_integrity_add_page);
195
bio_integrity_copy_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len,unsigned int direction)196 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
197 int nr_vecs, unsigned int len,
198 unsigned int direction)
199 {
200 bool write = direction == ITER_SOURCE;
201 struct bio_integrity_payload *bip;
202 struct iov_iter iter;
203 void *buf;
204 int ret;
205
206 buf = kmalloc(len, GFP_KERNEL);
207 if (!buf)
208 return -ENOMEM;
209
210 if (write) {
211 iov_iter_bvec(&iter, direction, bvec, nr_vecs, len);
212 if (!copy_from_iter_full(buf, len, &iter)) {
213 ret = -EFAULT;
214 goto free_buf;
215 }
216
217 bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
218 } else {
219 memset(buf, 0, len);
220
221 /*
222 * We need to preserve the original bvec and the number of vecs
223 * in it for completion handling
224 */
225 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
226 }
227
228 if (IS_ERR(bip)) {
229 ret = PTR_ERR(bip);
230 goto free_buf;
231 }
232
233 if (write)
234 bio_integrity_unpin_bvec(bvec, nr_vecs);
235 else
236 memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));
237
238 ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
239 offset_in_page(buf));
240 if (ret != len) {
241 ret = -ENOMEM;
242 goto free_bip;
243 }
244
245 bip->bip_flags |= BIP_COPY_USER;
246 bip->bip_vcnt = nr_vecs;
247 return 0;
248 free_bip:
249 bio_integrity_free(bio);
250 free_buf:
251 kfree(buf);
252 return ret;
253 }
254
bio_integrity_init_user(struct bio * bio,struct bio_vec * bvec,int nr_vecs,unsigned int len)255 static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec,
256 int nr_vecs, unsigned int len)
257 {
258 struct bio_integrity_payload *bip;
259
260 bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
261 if (IS_ERR(bip))
262 return PTR_ERR(bip);
263
264 memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
265 bip->bip_iter.bi_size = len;
266 bip->bip_vcnt = nr_vecs;
267 return 0;
268 }
269
bvec_from_pages(struct bio_vec * bvec,struct page ** pages,int nr_vecs,ssize_t bytes,ssize_t offset)270 static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
271 int nr_vecs, ssize_t bytes, ssize_t offset)
272 {
273 unsigned int nr_bvecs = 0;
274 int i, j;
275
276 for (i = 0; i < nr_vecs; i = j) {
277 size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
278 struct folio *folio = page_folio(pages[i]);
279
280 bytes -= size;
281 for (j = i + 1; j < nr_vecs; j++) {
282 size_t next = min_t(size_t, PAGE_SIZE, bytes);
283
284 if (page_folio(pages[j]) != folio ||
285 pages[j] != pages[j - 1] + 1)
286 break;
287 unpin_user_page(pages[j]);
288 size += next;
289 bytes -= next;
290 }
291
292 bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
293 offset = 0;
294 nr_bvecs++;
295 }
296
297 return nr_bvecs;
298 }
299
bio_integrity_map_user(struct bio * bio,struct iov_iter * iter)300 int bio_integrity_map_user(struct bio *bio, struct iov_iter *iter)
301 {
302 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
303 unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
304 struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
305 struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
306 size_t offset, bytes = iter->count;
307 unsigned int direction, nr_bvecs;
308 int ret, nr_vecs;
309 bool copy;
310
311 if (bio_integrity(bio))
312 return -EINVAL;
313 if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
314 return -E2BIG;
315
316 if (bio_data_dir(bio) == READ)
317 direction = ITER_DEST;
318 else
319 direction = ITER_SOURCE;
320
321 nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS + 1);
322 if (nr_vecs > BIO_MAX_VECS)
323 return -E2BIG;
324 if (nr_vecs > UIO_FASTIOV) {
325 bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
326 if (!bvec)
327 return -ENOMEM;
328 pages = NULL;
329 }
330
331 copy = !iov_iter_is_aligned(iter, align, align);
332 ret = iov_iter_extract_pages(iter, &pages, bytes, nr_vecs, 0, &offset);
333 if (unlikely(ret < 0))
334 goto free_bvec;
335
336 nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
337 if (pages != stack_pages)
338 kvfree(pages);
339 if (nr_bvecs > queue_max_integrity_segments(q))
340 copy = true;
341
342 if (copy)
343 ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes,
344 direction);
345 else
346 ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes);
347 if (ret)
348 goto release_pages;
349 if (bvec != stack_vec)
350 kfree(bvec);
351
352 return 0;
353
354 release_pages:
355 bio_integrity_unpin_bvec(bvec, nr_bvecs);
356 free_bvec:
357 if (bvec != stack_vec)
358 kfree(bvec);
359 return ret;
360 }
361
bio_uio_meta_to_bip(struct bio * bio,struct uio_meta * meta)362 static void bio_uio_meta_to_bip(struct bio *bio, struct uio_meta *meta)
363 {
364 struct bio_integrity_payload *bip = bio_integrity(bio);
365
366 if (meta->flags & IO_INTEGRITY_CHK_GUARD)
367 bip->bip_flags |= BIP_CHECK_GUARD;
368 if (meta->flags & IO_INTEGRITY_CHK_APPTAG)
369 bip->bip_flags |= BIP_CHECK_APPTAG;
370 if (meta->flags & IO_INTEGRITY_CHK_REFTAG)
371 bip->bip_flags |= BIP_CHECK_REFTAG;
372
373 bip->app_tag = meta->app_tag;
374 }
375
bio_integrity_map_iter(struct bio * bio,struct uio_meta * meta)376 int bio_integrity_map_iter(struct bio *bio, struct uio_meta *meta)
377 {
378 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
379 unsigned int integrity_bytes;
380 int ret;
381 struct iov_iter it;
382
383 if (!bi)
384 return -EINVAL;
385 /*
386 * original meta iterator can be bigger.
387 * process integrity info corresponding to current data buffer only.
388 */
389 it = meta->iter;
390 integrity_bytes = bio_integrity_bytes(bi, bio_sectors(bio));
391 if (it.count < integrity_bytes)
392 return -EINVAL;
393
394 /* should fit into two bytes */
395 BUILD_BUG_ON(IO_INTEGRITY_VALID_FLAGS >= (1 << 16));
396
397 if (meta->flags && (meta->flags & ~IO_INTEGRITY_VALID_FLAGS))
398 return -EINVAL;
399
400 it.count = integrity_bytes;
401 ret = bio_integrity_map_user(bio, &it);
402 if (!ret) {
403 bio_uio_meta_to_bip(bio, meta);
404 bip_set_seed(bio_integrity(bio), meta->seed);
405 iov_iter_advance(&meta->iter, integrity_bytes);
406 meta->seed += bio_integrity_intervals(bi, bio_sectors(bio));
407 }
408 return ret;
409 }
410
411 /**
412 * bio_integrity_prep - Prepare bio for integrity I/O
413 * @bio: bio to prepare
414 *
415 * Description: Checks if the bio already has an integrity payload attached.
416 * If it does, the payload has been generated by another kernel subsystem,
417 * and we just pass it through. Otherwise allocates integrity payload.
418 * The bio must have data direction, target device and start sector set priot
419 * to calling. In the WRITE case, integrity metadata will be generated using
420 * the block device's integrity function. In the READ case, the buffer
421 * will be prepared for DMA and a suitable end_io handler set up.
422 */
bio_integrity_prep(struct bio * bio)423 bool bio_integrity_prep(struct bio *bio)
424 {
425 struct bio_integrity_payload *bip;
426 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
427 unsigned int len;
428 void *buf;
429 gfp_t gfp = GFP_NOIO;
430
431 if (!bi)
432 return true;
433
434 if (!bio_sectors(bio))
435 return true;
436
437 /* Already protected? */
438 if (bio_integrity(bio))
439 return true;
440
441 switch (bio_op(bio)) {
442 case REQ_OP_READ:
443 if (bi->flags & BLK_INTEGRITY_NOVERIFY)
444 return true;
445 break;
446 case REQ_OP_WRITE:
447 if (bi->flags & BLK_INTEGRITY_NOGENERATE)
448 return true;
449
450 /*
451 * Zero the memory allocated to not leak uninitialized kernel
452 * memory to disk for non-integrity metadata where nothing else
453 * initializes the memory.
454 */
455 if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
456 gfp |= __GFP_ZERO;
457 break;
458 default:
459 return true;
460 }
461
462 /* Allocate kernel buffer for protection data */
463 len = bio_integrity_bytes(bi, bio_sectors(bio));
464 buf = kmalloc(len, gfp);
465 if (unlikely(buf == NULL)) {
466 goto err_end_io;
467 }
468
469 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
470 if (IS_ERR(bip)) {
471 kfree(buf);
472 goto err_end_io;
473 }
474
475 bip->bip_flags |= BIP_BLOCK_INTEGRITY;
476 bip_set_seed(bip, bio->bi_iter.bi_sector);
477
478 if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
479 bip->bip_flags |= BIP_IP_CHECKSUM;
480
481 /* describe what tags to check in payload */
482 if (bi->csum_type)
483 bip->bip_flags |= BIP_CHECK_GUARD;
484 if (bi->flags & BLK_INTEGRITY_REF_TAG)
485 bip->bip_flags |= BIP_CHECK_REFTAG;
486 if (bio_integrity_add_page(bio, virt_to_page(buf), len,
487 offset_in_page(buf)) < len) {
488 printk(KERN_ERR "could not attach integrity payload\n");
489 goto err_end_io;
490 }
491
492 /* Auto-generate integrity metadata if this is a write */
493 if (bio_data_dir(bio) == WRITE)
494 blk_integrity_generate(bio);
495 else
496 bip->bio_iter = bio->bi_iter;
497 return true;
498
499 err_end_io:
500 bio->bi_status = BLK_STS_RESOURCE;
501 bio_endio(bio);
502 return false;
503 }
504 EXPORT_SYMBOL(bio_integrity_prep);
505
506 /**
507 * bio_integrity_verify_fn - Integrity I/O completion worker
508 * @work: Work struct stored in bio to be verified
509 *
510 * Description: This workqueue function is called to complete a READ
511 * request. The function verifies the transferred integrity metadata
512 * and then calls the original bio end_io function.
513 */
bio_integrity_verify_fn(struct work_struct * work)514 static void bio_integrity_verify_fn(struct work_struct *work)
515 {
516 struct bio_integrity_payload *bip =
517 container_of(work, struct bio_integrity_payload, bip_work);
518 struct bio *bio = bip->bip_bio;
519
520 blk_integrity_verify(bio);
521
522 kfree(bvec_virt(bip->bip_vec));
523 bio_integrity_free(bio);
524 bio_endio(bio);
525 }
526
527 /**
528 * __bio_integrity_endio - Integrity I/O completion function
529 * @bio: Protected bio
530 *
531 * Description: Completion for integrity I/O
532 *
533 * Normally I/O completion is done in interrupt context. However,
534 * verifying I/O integrity is a time-consuming task which must be run
535 * in process context. This function postpones completion
536 * accordingly.
537 */
__bio_integrity_endio(struct bio * bio)538 bool __bio_integrity_endio(struct bio *bio)
539 {
540 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
541 struct bio_integrity_payload *bip = bio_integrity(bio);
542
543 if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && bi->csum_type) {
544 INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
545 queue_work(kintegrityd_wq, &bip->bip_work);
546 return false;
547 }
548
549 kfree(bvec_virt(bip->bip_vec));
550 bio_integrity_free(bio);
551 return true;
552 }
553
554 /**
555 * bio_integrity_advance - Advance integrity vector
556 * @bio: bio whose integrity vector to update
557 * @bytes_done: number of data bytes that have been completed
558 *
559 * Description: This function calculates how many integrity bytes the
560 * number of completed data bytes correspond to and advances the
561 * integrity vector accordingly.
562 */
bio_integrity_advance(struct bio * bio,unsigned int bytes_done)563 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
564 {
565 struct bio_integrity_payload *bip = bio_integrity(bio);
566 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
567 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
568
569 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
570 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
571 }
572
573 /**
574 * bio_integrity_trim - Trim integrity vector
575 * @bio: bio whose integrity vector to update
576 *
577 * Description: Used to trim the integrity vector in a cloned bio.
578 */
bio_integrity_trim(struct bio * bio)579 void bio_integrity_trim(struct bio *bio)
580 {
581 struct bio_integrity_payload *bip = bio_integrity(bio);
582 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
583
584 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
585 }
586 EXPORT_SYMBOL(bio_integrity_trim);
587
588 /**
589 * bio_integrity_clone - Callback for cloning bios with integrity metadata
590 * @bio: New bio
591 * @bio_src: Original bio
592 * @gfp_mask: Memory allocation mask
593 *
594 * Description: Called to allocate a bip when cloning a bio
595 */
bio_integrity_clone(struct bio * bio,struct bio * bio_src,gfp_t gfp_mask)596 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
597 gfp_t gfp_mask)
598 {
599 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
600 struct bio_integrity_payload *bip;
601
602 BUG_ON(bip_src == NULL);
603
604 bip = bio_integrity_alloc(bio, gfp_mask, 0);
605 if (IS_ERR(bip))
606 return PTR_ERR(bip);
607
608 bip->bip_vec = bip_src->bip_vec;
609 bip->bip_iter = bip_src->bip_iter;
610 bip->bip_flags = bip_src->bip_flags & BIP_CLONE_FLAGS;
611 bip->app_tag = bip_src->app_tag;
612
613 return 0;
614 }
615
bioset_integrity_create(struct bio_set * bs,int pool_size)616 int bioset_integrity_create(struct bio_set *bs, int pool_size)
617 {
618 if (mempool_initialized(&bs->bio_integrity_pool))
619 return 0;
620
621 if (mempool_init_slab_pool(&bs->bio_integrity_pool,
622 pool_size, bip_slab))
623 return -1;
624
625 if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
626 mempool_exit(&bs->bio_integrity_pool);
627 return -1;
628 }
629
630 return 0;
631 }
632 EXPORT_SYMBOL(bioset_integrity_create);
633
bioset_integrity_free(struct bio_set * bs)634 void bioset_integrity_free(struct bio_set *bs)
635 {
636 mempool_exit(&bs->bio_integrity_pool);
637 mempool_exit(&bs->bvec_integrity_pool);
638 }
639
bio_integrity_init(void)640 void __init bio_integrity_init(void)
641 {
642 /*
643 * kintegrityd won't block much but may burn a lot of CPU cycles.
644 * Make it highpri CPU intensive wq with max concurrency of 1.
645 */
646 kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
647 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
648 if (!kintegrityd_wq)
649 panic("Failed to create kintegrityd\n");
650
651 bip_slab = kmem_cache_create("bio_integrity_payload",
652 sizeof(struct bio_integrity_payload) +
653 sizeof(struct bio_vec) * BIO_INLINE_VECS,
654 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
655 }
656